Cosmological implications and structure formation from a time varying vacuum

Abstract

We study the dynamics of the FLRW flat cosmological models in which the vacuum energy varies with time, $\Lambda (t)$. In this model we find that the main cosmological functions such as the scale factor of the universe and the Hubble flow are defined in terms of exponential functions. Applying a joint likelihood analysis of the recent supernovae type Ia data, the Cosmic Microwave Background shift parameter and the Baryonic Acoustic Oscillations traced by the Sloan Digital Sky Survey (SDSS) galaxies, we place tight constraints on the main cosmological parameters of the $\Lambda (t)$ scenario. Also, we compare the $\Lambda (t)$ model with the traditional $\Lambda$ cosmology and we find that the former model provides a Hubble expansion which compares well with that of the $\Lambda$ cosmology. However, the $\Lambda (t)$ scenario predicts stronger small scale dynamics, which implies a faster growth rate of perturbations with respect to the usual $\Lambda$-cosmology, despite the fact that they share the same equation of state parameter. In this framework, we find that galaxy clusters in the $\Lambda (t)$ model appear to form earlier than in the $\Lambda$ model.

Accepted for publication, MNRAS, 10 pages, 5 figures

References in corpus (52)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• The Cosmological Constant and Dark Energy
• Detection of the Baryon Acoustic Peak in the Large-Scale Correlation Function of SDSS Luminous Red Galaxies
• Cosmological Imprint of an Energy Component with General Equation of State
• Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant
• Cosmological Constant - the Weight of the Vacuum
• Exploring the Expansion History of the Universe
• Accelerating Universes with Scaling Dark Matter
• The holographic principle
• Improved Cosmological Constraints from New, Old and Combined Supernova Datasets
• Cosmological Constraints from the SDSS Luminous Red Galaxies
• Using the Evolution of Clusters to Constrain Omega
• Cluster Abundance Constraints on Quintessence Models
• The 2dF Galaxy Redshift Survey: correlation functions, peculiar velocities and the matter density of the Universe
• The 2dF Galaxy Redshift Survey: The bias of galaxies and the density of the Universe
• CDM Models with a Smooth Component
• Interacting Quintessence
• Scrutinizing Exotic Cosmological Models Using ESSENCE Supernova Data Combined with Other Cosmological Probes
• Gravity and the Thermodynamics of Horizons
• Evolution of the Scale Factor with a Variable Cosmological Term
• The State of the Dark Energy Equation of State
• The Linear Theory Power Spectrum from the Lyman-alpha Forest in the Sloan Digital Sky Survey
• The Clustering of Luminous Red Galaxies in the Sloan Digital Sky Survey Imaging Data
• Crossing the Phantom Divide: Theoretical Implications and Observational Status
• Nonminimal coupling and quintessence
• Cosmology with Interaction between Phantom Dark Energy and Dark Matter and the Coincidence Problem
• Super-acceleration as Signature of Dark Sector Interaction
• Evidence for a non-zero Lambda and a low matter density from a combined analysis of the 2dF Galaxy Redshift Survey and Cosmic Microwave Background Anisotropies
• Cosmologies with Energy Exchange
• On the scaling behavior of the cosmological constant and the possible existence of new forces and new light degrees of freedom
• The 2dF-SDSS LRG and QSO Survey: QSO clustering and the L-z degeneracy
• Can vacuum decay in our Universe?
• Testing LCDM with the Growth Function δ(a): Current Constraints
• The 2dF-SDSS LRG and QSO Survey: The LRG 2-Point Correlation Function and Redshift-Space Distortions
• The XMM Cluster Survey: A Massive Galaxy Cluster at z=1.45
• Interpreting Cosmological Vacuum Decay
• LXCDM: a cosmon model solution to the cosmological coincidence problem?
• Renormalization-group running of the cosmological constant and its implication for the Higgs boson mass in the Standard Model
• Dynamics of Interacting Quintessence Models: Observational Constraints
• Constraints on the interaction and self-interaction of dark energy from cosmic microwave background
• The Running of the Cosmological and the Newton Constant controlled by the Cosmological Event Horizon
• Observational constraints on late-time Lambda(t) cosmology
• Studying the decay of the vacuum energy with the observed density fluctuation spectrum
• Evolution of density perturbations in decaying vacuum cosmology
• Cluster Formation Rate in Models with Dark Energy
• Current and future supernova constraints on decaying $\Lambda$ cosmologies
• Exact solutions of Brans-Dicke cosmology with decaying vacuum density
• Model for a Universe described by a non-minimally coupled scalar field and interacting dark matter
• Cosmological constrains from X-ray AGN clustering and SNIa data
• A Better Way to Reconstruct Dark Energy Models ?

Cited by in corpus (25)

• Hubble expansion & Structure Formation in Time Varying Vacuum Models
• Expansion History with Decaying Vacuum: A Complete Cosmological Scenario
• Complete Cosmic History with a dynamical Lambda(H) term
• Vacuum models with a linear and a quadratic term in H: structure formation and number counts analysis
• Entropic-force dark energy reconsidered
• Unified dark energy and dark matter from a scalar field different from quintessence
• Dynamics and cosmological evolution in Λ-varying cosmology
• Nonsingular Decaying Vacuum Cosmology and Entropy Production
• Thermodynamical aspects of running vacuum models
• Unified Dark Energy and Dark Matter from Dynamical Space Time
• On the implementation of the spherical collapse model for dark energy models
• Unification of DE-DM from Diffusive Cosmology
• Dynamics in Varying vacuum Finsler-Randers Cosmology
• CMB Temperature and Matter Power Spectrum in a Decay Vacuum Dark Energy Model
• Solving the main cosmological puzzles with a generalized time varying vacuum energy
• Growth of spherical overdensities in scalar-tensor cosmologies
• Friedmann cosmology with decaying vacuum density in Brans-Dicke theory
• Cosmological singularities and analytical solutions in varying vacuum cosmologies
• The Integrated Sachs-Wolfe Effect in Time Varying Vacuum Model
• Dynamical systems of cosmological models for different possibilities of $G$ and ${\rho }_{\Lambda }$
• Effects of tidal gravitational fields in clustering dark energy models
• Primordial Gravitational Waves in Running Vacuum Cosmologies
• Improved Lemaitre-Tolman model and the mass and turn-around radius in group of galaxies II: the role of dark energy
• Improved Lemaitre-Tolman model and the mass and turn-around radius in group of galaxies
• Viscous fluid dynamics with decaying vacuum energy density